JP3487754B2 - Deodorizing filter medium and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deodorizing filter medium for filtering and cleaning a fluid contaminated with an odor component, and more particularly to a deodorizing filter medium excellent in deodorizing performance and processability and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable increase in awareness of the living environment, and in particular, there is a great deal of interest in odors. Removal is also required. Various deodorizing filter media have been proposed to remove these odorous components. Most of such deodorizing filter materials adhere particles (for example, collectively referred to as deodorizing powder particles) made of, for example, activated carbon or various chemical deodorizing agents to a sheet-like member having air permeability. As a conventionally known technique for adhering powdery particles, a method of fixing and carrying deodorant powdery particles on a base cloth such as a non-woven fabric using various binders has been widely used. However, many of them have a drawback that the surface of the deodorized powder or granules is coated with the binder, and the performance originally possessed by the powder or granules is deteriorated.

On the other hand, for example, Japanese Patent Application Laid-Open No. 8-266.
In the technique proposed in Japanese Patent Publication No. 845 (hereinafter referred to as “reference”), 1
An emulsion type acrylic pressure-sensitive adhesive is preliminarily attached to a mesh having a mesh size of 0 mm to 1 mm, and deodorant powder particles (adsorption material particles) are fixed via this pressure-sensitive adhesive. In this technique, as disclosed in the publication, 1 mm to 1
The pressure-sensitive adhesive is applied to a net having a 0 mm opening by a sprayer or a coater. Therefore, even if a mesh body having an opening of 100 μm or less is selected in order to achieve a desired deodorizing efficiency, the opening portion is crushed at the stage of applying the pressure-sensitive adhesive, and the pressure loss of the obtained filter medium becomes high.

As another technique for adhering powdery particles, a deodorizing powdery material is mixed with an adhesive made of a granular thermoplastic resin in advance, and the mixture is applied to the surface of a flexible sheet-shaped support material to obtain a filter medium. The technology to do is known. Usually, an adhesive having a particle size smaller than that of the deodorizing powder particles is used.However, in the deodorizing filter material having such a structure, the deodorizing powder particles are three-dimensionally point-bonded to each other through the binder particles, and a predetermined amount It is possible to form a three-dimensional structure in the thickness. Therefore, as compared with the technique disclosed in the above-mentioned document, it is possible to realize a deodorizing filter medium having a high density of deodorizing powder particles.

[0005]

As described above, in the technique of using the granular adhesive, the deodorizing powder particles and the binder particles are mixed in advance, and the particles are arranged and fixed on the supporting material. Here, if one deodorizing powder is focused, the degree of fixing one deodorizing powder can be determined by selecting the particle size of the binder particles and the relative composition ratio with the powder. It is possible to control. However, the binder particles only hold the deodorant granules at individual points. Therefore, as is well known, the mechanical strength is poor in order to realize a highly efficient deodorizing filter material by performing folding processing as a filter element, and in order to avoid the deodorizing powder granules falling off, the design at the time of the folding processing is limited. There was a problem of having. In addition, in the case of this point bonding technique, it is necessary to heat-melt the adhesive in order to achieve sufficient fixation, but the adhesive tends to fluidize during heat treatment, and the adhesive tends to be localized on the lower side in the direction of gravity. is there. Therefore, heat treatment conditions are difficult,
There is a problem that the pressure loss due to the adhesive becomes large, or the deodorized powder particles are coated with the fluidized adhesive.

In view of the above-mentioned conventional problems, the inventors of the present invention have excellent mechanical strength by providing the constituents for fixing the deodorant powder granules in a continuous state with each other. As a result of intensive studies to realize a deodorizing filter medium having a high density, the present invention has been created. Therefore, an object of the present invention is to provide a deodorizing filter medium having a low pressure loss, a high deodorizing efficiency, an excellent mechanical strength, and a high processability.

[0007]

In order to achieve this object, according to the constitution of the deodorizing filter material according to the first invention of the present application, a web composed of a connecting portion made of only hot melt resin and a resin aggregating portion is provided. On one surface, it has a laminated unit formed by fixing the deodorant powder through the resin agglomerate part, the other surface of the above-mentioned web, and the deodorant powder constituting the other laminated unit. It is characterized in that it is adhered through the resin agglomeration part.

Further, according to the method for producing a deodorizing filter medium according to the second invention of this application, after the deodorizing powder granules are arranged on the surface of the hot-melt nonwoven fabric, the hot-melt nonwoven fabric and the deodorizing powder are heated by heat treatment. A first step of forming a resin agglomerated portion in a portion in contact with the granules and forming a web composed of the resin agglomerated portion and a connecting portion made of a hot melt resin, and the deodorized powder granules described above. Of these, a second step of forming only a deodorizing powder granule fixed to the above-mentioned web to form a laminated unit, and a hot melt non-woven fabric in contact with the deodorizing powder granule fixed to this laminating unit. It is characterized in that the layers are laminated and the above-mentioned first step and second step are sequentially performed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION First, an embodiment of a deodorizing filter medium according to the first invention of this application will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing the structure of the filter medium of the present invention.

Web 15 constituting the deodorizing filter material of the present invention
Is composed of a connecting portion 11 and a resin aggregating portion 13, and
Composed of hot melt resin. The web 15 having such a structure is obtained by heat-treating the hot-melt nonwoven fabric referred to in the manufacturing method according to the second aspect of the invention under the contact of the deodorizing powder granules 17 (detailed later).

As the hot-melt resin capable of forming such a web, a thermoplastic polyamide resin, a thermoplastic polyester resin, a thermoplastic polyurethane resin, a polyolefin resin, a polyolefin-modified resin, or the like can be used.
Each can be used alone or as a mixture. Examples of the polyolefin-modified resin referred to here include ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer. Combined, ethylene-maleic acid copolymer, ionomer resin
(A heat-sensitive resin obtained by adding a metal to an ethylene-methacrylic acid copolymer) and the like. As the hot melt resin that can be used in the present invention and the method invention of the present application described in detail later, one having MI of 50 or more and 500 or less may be selected. A resin having an MI lower than this preferable range has low fluidity during heat treatment, a resin agglomerate is less likely to be formed during heat treatment, and the deodorant powder granules may not be completely fixed. Further, if the resin content is higher than the above range, the fluidity at the time of heat treatment is high, and it becomes difficult to maintain the shape of the laminated unit.

[0012] As the deodorizing powdery granules, conventionally known activated carbon and other particulate chemical deodorizing agents can be selected and used, but in order to realize high efficiency and low pressure loss The average particle size of the granules is preferably 0.147 mm (100 mesh) or more and 1.65 mm (10 mesh) or less. When a deodorizing powder having an average particle size smaller than the lower limit of this preferable range is used, the initial deodorizing efficiency can be made high, but the pressure loss becomes large.

Further, when a deodorizing powder having an average particle size larger than the upper limit of the above-mentioned preferred range is used, the deodorizing efficiency tends to decrease. The amount of the deodorizing powder particles carried in one laminated unit constituting the deodorizing filter material of the present invention generally depends on the average particle size of the powder particles, and the deodorizing efficiency becomes low when the particle size is relatively large. However, by designing a large number of laminated units, the deodorizing efficiency required for the deodorizing filter medium can be achieved. At this time, the average particle diameters of the deodorant powder granules constituting each laminated unit may be different from each other. Further, in consideration of the processing suitability of the deodorizing filter medium, that is, the flexibility required for folding, the flexibility required for winding, etc., the thickness of the filter medium is preferably 5 mm or less, and preferably 1 mm. About 4 mm is good.

Next, an embodiment of the manufacturing method which is the second invention of this application will be described. As described above, in the present invention, the hot-melt nonwoven fabric is laminated, and the heat treatment is performed in the state where the deodorized powder granules are placed in contact therewith. The hot melt nonwoven fabric used in this case is composed of the various resins described above and has an area density of 10 to 30 g /
m ² is preferable, and 15 to 25 g / m ² is particularly preferable. When the areal density is smaller than these preferable ranges, the non-woven fabric lacks uniformity, and as a result, the uniformity of the deodorizing powder particles fixed to the laminate unit is impaired, and the efficiency of the deodorizing filter medium is reduced due to the leakage of odorous substances. descend. Further, even if it exceeds the above-mentioned preferable range, the improvement of the fixing strength cannot be expected, and only the pressure loss as the deodorizing filter medium will increase.

Further, the opening diameter of the hot-melt nonwoven fabric used in the present invention is preferably smaller than the desired particle diameter of the powder or granular material in order to uniformly support the deodorizing powder or granular material on the obtained deodorizing filter material. . For example, the particle size of the deodorant powder is 32
When the mesh (about 500 μm) is used, it is preferable to select and use the above-mentioned hot melt nonwoven fabric so that the web opening diameter after heat treatment is 100 μm or less.

In this method invention, the fibers constituting the hot melt non-woven fabric are plasticized and melted by the heat treatment, and a part of the fibers are melted and cut due to the small fiber diameter and gathered at the contact point with the deodorized powder granules, and the resin agglomerated part Is thought to form. This point will be described with reference to FIG. 2 showing a plane focusing on one deodorant powder granule 17 from the web 15 side in the laminated unit shown in FIG. If the fiber diameter is comparatively large, it will not be cut even if it is plasticized and melted, and the connecting portion 11 will have a strong net-like structure. In this heat treatment, conventionally known means such as a calender, a hot air heater, an infrared heater, steam heating, or a device for sandwiching and heating a cloth between a pair of endless belts facing each other can be used. Of these, by performing heat treatment with a fluid having a calorific value, it is possible to form a communication hole (indicated by an arrow A in FIG. 1) in the thickness direction of the laminated unit. Furthermore, as a particularly preferred embodiment, a hot-melt nonwoven fabric made of a thermoplastic polyamide resin or an ethylene-vinyl acetate copolymer resin is used, and by adopting a heat treatment with steam, the resin is likely to shrink and cut when wet and hot. Therefore, the cutting can be efficiently performed. Further, when it is necessary to compensate for the strength decrease due to plasticizing and melting of the hot melt nonwoven fabric, a filter material for collecting dust may be added as a support of the hot melt nonwoven fabric forming the outermost layer of the deodorizing filter medium. .

As another aspect of the method invention according to this application, when a treatment method other than fluid heating, such as calendering, is adopted, deodorant powder granules are sprinkled on the release paper and the surface thereof is sprayed. The deodorizing filter medium according to the first invention can also be obtained by stacking hot-melt nonwoven fabrics, further stacking release paper and heat-treating them to sequentially form laminated units.

Examples of the present invention will be described below, but the following examples are merely preferred examples for facilitating the understanding of the present invention, and the present invention is limited only to these exemplified conditions. is not.

[0019]

Example First, a spunbond having a surface density of 30 g / m ^{2 made} of polyester was used as a support, and a surface density of 20 g / m made of a thermoplastic polyamide resin was used for the support.
Laminate m ² hot melt non-woven fabric. Then, classified commercial activated carbon (described later in detail) is sprayed on the surface of the hot-melt nonwoven fabric laminated in this way. Then, about 5
A web composed of a connection part made of hot melt resin and a resin agglomeration part is obtained by subjecting the hot melt non-woven fabric to plasticization and melting by subjecting the support side (hot melt non-woven fabric side) to steam treatment of Kg / cm ² for about 7 seconds. Then, activated carbon was fixed to the resin through the resin aggregating portion. Subsequently, the activated carbon other than the fixed activated carbon was removed to obtain a first-layer laminated unit in which the activated carbon was fixed according to each particle size and was bonded to the support. Further, the hot melt non-woven fabric was laminated on the lamination unit in this state, and the second layer or the third layer of the lamination unit was formed through activated carbon spraying, steam treatment, and removal of unfixed activated carbon. A deodorizing filter material according to 1 to 5 was obtained. In addition, the same constituent materials as in Example 2 were used, except that a hot-melt nonwoven fabric made of a hot-melt resin other than the thermoplastic polyamide resin was used.
Deodorizing filter media according to Nos. 10 to 10 were produced. Furthermore, Example 11
The deodorizing filter material obtained in Example 2 was sandwiched between a pair of opposed endless belts, and the temperature was 130 ° C. and the pressure was 0.01.
A filter medium was prepared by thermocompression bonding for 10 seconds under the condition of MPa.

For comparison, the average particle size is 0.375 m.
“VESTAMELT 430P2” (manufactured by Daicel Hüls KK, trade name: average particle size 0.16 mm), which is a polyamide-based granular adhesive, per 100 parts by weight of m of activated carbon 25
15 parts by weight are mixed in a dry state, and the mixture is coated and formed with the above polyester spunbond as a support.
By heating at 0 ° C. for 5 minutes, a deodorizing filter medium according to a comparative example in which activated carbons were spot-bonded to each other with the above adhesive was produced.
Table 1 shows the details of the filter media according to Examples 1 to 11 and Comparative Example, and Table 2 shows the pressure loss measurement results, the deodorization efficiency measurement results, and the processability evaluation results.

[0021]

[Table 1]

[0022]

[Table 2]

The method of measuring the deodorizing performance will be described below. First, in measuring pressure loss, according to the standard method,
Air was blown to each of the deodorizing filter media at a wind speed of 10 cm / sec, and the pressure difference between the upstream and downstream sides of the filter media was determined. As a result, as is clear from the comparison between the comparative example composed of the granular adhesive and Example 5, the filter medium to which the present invention was applied was composed of deodorized powder particles having substantially the same amount and the same average particle size. Nevertheless, the pressure loss was about ⅔ compared with the comparative example, showing a remarkable effect. Further, it can be understood that the filter media of the present invention according to Examples 1 to 11 all have low pressure loss. Further, when the filter medium according to the comparative example was observed with the naked eye, film-like portions which were considered to be caused by the granular adhesive were scattered on the support-side surface of the filter medium.

The deodorization efficiency was measured by using toluene as an odor substance under the conditions of an initial concentration of 25 ppm and an air velocity of 14 cm / sec. In this measurement, 1 minute after the start of measurement, the test conditions were considered to have reached a steady state, and the measurement was made initial, and thereafter, every 10 minutes, measurement was performed for 30 minutes. Regarding the results, the difference between the initial concentration (upstream concentration) and the downstream concentration after passing through the filter medium was divided by the initial concentration and calculated as a percentage. As can be understood from Table 2, the structural superiority by application of the present invention was confirmed from Example 5 and Comparative Example. When the filter medium of this comparative example was observed with an electron microscope, it was found that a part of the surface of the activated carbon was covered with a component considered to be an adhesive agent that did not contribute to the fixation. Further, from the results of Examples 1 to 10, the smaller the average particle size of the deodorant powder granules, the better the initial characteristics.
In addition, although the deodorization efficiency measurement result of the filter medium according to Example 11 is omitted, it is almost the same as that of Example 2, and the thickness is reduced by being manufactured through two heating means (improved workability. ) Was achieved, a large increase in pressure loss did not occur, and excellent deodorizing performance was exhibited.

Further, when each of the 11 kinds of filter media described above was folded at an angle of 90 °, the 11 kinds of filter media according to the examples showed substantially no damage at the folded parts. On the other hand, in the filter medium according to the comparative example, cracks that could be visually confirmed were generated, and a part of the deodorized powder particles had fallen off.

As can be understood from the above description, each of the filter media of the examples to which the present invention was applied was excellent in both deodorizing efficiency and pressure loss and had good workability. On the other hand, in the technique using the granular adhesive given as the comparative example, about 19% of the weight of the filter medium is the adhesive, whereas in Example 5 the amount of the deodorized powder granules carried is almost the same, It is about 11%. From this, in the technique according to the present invention using the hot melt nonwoven fabric, in fixing the deodorant powder granules, the ratio of the constituents not involved in deodorization without impairing the processability is minimized, and thereby high deodorization is achieved. It has become clear that efficiency and low pressure drop can be achieved.

[0027]

As is apparent from the above description, by applying the invention of this application, it is possible to realize a deodorizing filter medium in which deodorizing powder particles are fixed to a web which is a continuous constituent. Therefore, it is possible to provide a deodorizing filter medium having high deodorizing efficiency, low pressure loss, and excellent workability.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a part of a deodorizing filter medium for explaining the present invention.

FIG. 2 is a diagram schematically showing a part of a deodorizing filter medium for explaining the present invention.

[Explanation of symbols]

11: Connection part 13: Resin aggregation part 1
5: Web 17: Deodorized powder granules 19: Lamination unit
A: Communication hole.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI B01D 53/81

Claims (6)

(57) [Claims] 1. A laminated unit in which deodorized powder granules are fixed to one surface of a web composed of a connecting part made of only hot-melt resin and a resin agglomerate part through the resin agglomerate part. A deodorizing filter material, characterized in that the other surface of the web and deodorizing powder particles constituting another laminated unit are adhered to each other via a resin aggregating portion. 2. The deodorizing filter material according to claim 1, wherein the hot melt resin is made of a thermoplastic polyamide resin, a thermoplastic polyester resin, a thermoplastic polyurethane resin, a polyolefin resin or a polyolefin modified resin. 3. The thickness of the web according to claim 1, wherein
A contract characterized by being smaller than the average particle size of deodorized powder
The deodorizing filter medium according to claim 1. 4. A hot-melt non-woven fabric is provided with deodorant powder granules, and then a heat treatment is performed to form a resin agglomerate at a portion where the hot melt non-woven fabric and the deodorant powder granules are in contact with each other, and the resin agglomerate is formed. And a first step of forming a web consisting of a connecting portion made of hot-melt resin, of the deodorized powder granules, only the deodorized powder granules fixed to the web are left to form a laminated unit Second step, a hot melt nonwoven fabric is laminated in contact with the deodorizing powder granules of the lamination unit, and subsequently, the deodorizing powder granules are arranged on the surface of the hot melt nonwoven fabric, and then the first step and the above A method for producing a deodorizing filter medium, which comprises sequentially performing the second step. 5. The process for producing a deodorizing filter medium according to claim 4, characterized in that the heat treatment in the first step was steamed. 6. If the opening diameter of the hot melt nonwoven fabric is
It is characterized in that it is made smaller than the particle size of the deodorizing powder granules.
The method for producing the deodorizing filter medium according to claim 4.